Wear-resistant refractory lining article



Dec. 20, 1966 K. H.SANDMEYER ETAL 3,

WEAR-RESISTANT REFRACTORY LINING ARTICLE Filed May 1, 1963 2Sheets-Sheet l Fig".

Fig.3 Fig 4 /.5a F' 1 INVENTORS KARL H. SANDMEYER EUGENE L. O'MEARA JRATTORNEY Dec. 20, 1966 K. H. SANDMEYER ETAL 3,

WEAR-RESISTANT REFRACTORY LINING ARTICLE 2 Sheets-Sheet 2 Filed May 1,1963 INVENTORf: KARL H. SANDMEYER EUGENE L.'OMEARA JR LWJM ATTORNEYUnited States Patent 3,292,333 WEAR-RESISTANT REFRACTORY LINING ARTICLEKarl H. Sandmeyer and Eugene L. OMeara, Jr., Jamestown, N.Y., assignorsto Harbison-Carhorundum Corporation, Falconer, N.Y., a corporation ofDelaware Filed May 1, 1963, Ser. No. 277,359 3 Claims. (Cl. 52-509) Thisinvention relates to improvements in refractory articles of manufactureadapted for use as wear-resistant elements in any construction in whichresistance to wear is a principal requirement. More particularly itrelates to a fused cast refractory block suitable for use as a liningblock, having an improved means for securing the block to a metal base.This invention is particularly adapted for use in conjunction with thedischarge chute of a furnace Where abrasion is especially severe.However, this invention is not to be construed as limited to anyparticular type of chute but has application in conjunction with anystructure in which resistance to abrasion is a principal requirement.One example of such an application is the fabrication of awear-resistant lining on the discharge chute of a coking furnace.

In the carbonization of coal by the by-product process, from -16 tons ofcoal are charged to an elongated coking chamber measuring about 10 to 14feet in height, 30 to 43 feet in length and 15 to 19 inches in width.After the oven is sealed, the charge is heated to about 2000" F. forl6-20 hours to form a mass of coke in the oven. This mass of coke,weighing approximately 10 tons, is removed from the oven by means of apusher, which is an electrically powered, rack-and-pinion-operated ramwhich pushes the coke cake from the oven, down a discharge chute, andinto a quenching car. As is readily apparent, the discharge chute mustbe extremely resistant to wear in order to withstand the sliding actionof the huge, intensely hot, coke mass without failure.

The selection of materials for use in constructing such a dischargechute has confronted the industry with two problems. First, an extremelyabrasion resistant material must be used and secondly, suitable meansmust be employed to hold the lining material securely in position, evenwhen a large mass slides across its surface.

It has been recognized by industry that certain refractories haveexcellent resistance to wear and therefore are suitable for use inconjunction with structures which are subject to abrasion. However, theproblem of a suitable means for securing the wear-resistant material inplace has still remained and has been the subject of extensiveinvestigation over the years.

One solution to the problem has proposed the use of fused castrefractory blocks or shapes as the lining material for a chute, saidblocks being fastened in place by metallic elements which are embeddedin the base of the block as it is cast. This proposed solution, however,has several disadvantages. In fabricating fused cast refractories, veryhigh temperatures are used in order to obtain a molten material.Refractory blocks are poured at about 2000 C. and must be cooled veryslowly in order to avoid cracking the block and to develop a strongblock. However, when a metallic element is to be embedded in fusedrefractory as it is cast, heat must be dissipated as rapidly as possiblein order to prevent excessive corrosion and oxidation of the metallicelement. Therefore it is necessary to sacrifice either the strength ofthe block or the metallic element or both, when making such a block.Also, the high temperatures present during the casting of the fusedrefractory limits the choice of metals for use as holddown elements tothose metals which can withstand temperatures in excess of 2000 C.without excessive oxida- Patented Dec. 20, 1966 tion or other form ofundesirable degradation. Furthermore, the embedding of the metallicelements within the cast refractory requires awkward production moldingmethods.

Other previously suggested means for securing wearresistant materials inplace on discharge chutes have not been satisfactory for variousreasons, and the present invention is the result of further efforts toprovide a more satisfactory solution to the foregoing and other problemsrelating to wear-resistant elements for this purpose.

It is therefore an object of this invention to provide an improved fusedcast, abrasion-resistant block. Another object of the invention is toprovide a wear-resistant article having an improved means for securingthe block to a metal base. Another object of the invention is to providean improved wear-resistant article having fomied recesses or cavities inone or more sides or ends for receiving an anchoring clip which can bejoined to a base plate to hold said article securely in position. Afurther object is to provide a fused cast refractory block havingbeveled sides or ends and having formed recesses in one or more sides orends for receiving a metal clip which may be bonded to the back wall ofthe recess with a temporary bond and welded to a metal base plate.

A still further object of the invention is to provide anabrasion-resistant chute comprising a metal chute and a lining in saidmetal chute comprising a plurality of fused cast refractory blocksjoined to the chute by separate metal clips.

Various other objects and advantages will appear from the followingdescription of several embodiments of the invention, and the novelfeatures will be particularly pointed out hereinafter in connection withthe appended claims.

As was mentioned hereinabove, the concept of molding a fused refractoryaround a metallic insert has not proved satisfactory for the metalinserts of blocks formed in this manner are oxidized considerably makingit difficult, if not impossible, to weld the inserts to the metal baseof a chute. It has now been discovered that fused cast refractory blocksmay be used to form an effective wearresistant lining on a metal base bysecuring the blocks to a base by means of a separate anchoring clipwhich is inserted in the block after the block has been cast and hascooled.

In accordance with one embodiment of this invention, fused castrefractory blocks, suitable for use as wearresistant elements in anyconstruction in which resistance to wear is a principal requirement, areformed having top and bottom surfaces and edge faces, the edge facescomprising two substantially parallel side edge faces and twosubstantially parallel end edge faces. Each of the blocks is providedwith a cavity or recess at the base of one or more side or end edgefaces, the cavity or recess extending into the block and having sidewalls and a rear wall for receiving an anchoring clip. The anchoringclip is inserted in the recess after the block has cooled and engagesthe rear wall of the recessed portion of the edge face and is joined toa supporting base, as by welding, to prevent upward movement of theblock. When a series of such blocks are placed on a supporting base andjoined to the base so that the blocks abut one another, the blocks arerestrained from movement in any direction, thereby forming a continuousdurable wear-resistant lining on the base, protecting the base fromabrasion.

In the construction described in the preceding paragraph the fused castrefractory blocks are held securely in position on the base without thedisadvantages inherent in the prior art structures. Thus, since theanchoring clips are not inserted in the block until the block has beencast and has cooled, the refractory may be cooled as slowly as desiredin order to form a strong block without adversely affecting theanchoring clips. This not only permits a stronger block to be formed butalso enables a stronger joint to be formed between the anchoring clipand the supporting base.

Another advantage of wear-resistant :blocks made in accordance with thisinvention is that since the anchoring clips are not inserted into theblock until the cast block has cooled, the clips need not be made ofmetals which must be able to withstand the high temperatures present incasting fused refractories. This permits a much wider choice of metalsfor use as the anchoring clips. This wider availability of metalsresults in another advantage in that the anchoring clips need not bejoined to the base only by welding, as in the case of prior art devices.Thus, by a proper selection of metals for use as the anchoring clips,the blocks may be joined to the base by other methods, such as brazingor hard soldermg.

In forming abrasion-resistant, lining blocks embodying this invention, asuitable molten refractory is poured into a mold, the mold having aninsert on one edge thereof so that when the insert is removed a recessis formed at the base of the side of the cast refractory block, therecess having side walls, a top wall and a rear wall. The "block iscooled and thereafter the mold is stripped, the insert is removed fromthe block and the block is then annealed. The insert may be of anydesired shape but generally it is preferred to use an insert whichresults in the rear wall of the formed recess having a curved, sloping,or an irregular or a stepped profile.

In order to secure such a block to a metal base to form a wear-resistantlining thereon a metal anchoring clip, conforming substantially inprofile to the profile of the rear wall of the recess, is then insertedat least partially within the recess of the block. The anchoring clipmay engage the entire rear wall of the recess or it may engage only aportion of said rear wall. In order to facilitate handling of the blockand clip, the clip may be bonded to the rear wall such as by means of anepoxy resin. The block is then placed on a metal supporting base and theanchoring clip joined to the base as by welding. This firmly secures theblock in position on the base and prevents any upward movement of theblock. A series of such blocks is secured to the base so that the blocksabut one another forming a continuous, durable wear-resistant lining onthe base, held securely in position against lateral and upward movement.

It is apparent that this structure is capable of many variations andmodifications without departing from the inventive concept. Thus, thefused cast refractory block may be molded with one or both of the end orside edge faces either straight or beveled and with one or moreclip-receiving recesses in one or more of the edge faces. It isgenerally preferred to east the block with two opposing parallel edgefaces beveled in the same direction and with a clip-receiving recess atthe base of one beveled edge face, preferably at the base of the bevelededge face which slopes beneath the overhanging top surface of the block.This construction facilitates the manufacture and installation of theblocks, for when the blocks are positioned on the base in side by siderelationship with juxtaposed beveled edge faces parallel and theanchoring clip welded to the base, the top surface of the welded downend of one block overlaps the bottom surface of the abutting blockthereby restraining the abutting block from the upward movement.

The clip-receiving recess or cavity, formed at the base of an edge faceof the block has side walls and a rear wall, the walls of the recessdesirably terminating below the top surface of the block. The rear wallof the recess may be formed in a variety of shapes and forms. Thus, therear wall of the recessed portion of the edge face may have a curvedprofile, an irregular or step profile or any shape which presents asurface which may be enthe herein described articles, reference is madeto the clip is made so as to conform at least partially to the. When theback;

profile of the rear wall of the recess. wall of the recess is in theform of a sloping wall, the anchoring clip may be merely a straightpiece of metal which can be positioned against the sloping wall.

The anchoring clip may be positioned entirely within the recess of oneblock or it may :be constructed so as to engage the rear walls ofrecesses of adjoining blocks. That is, the clip may engage the rear wallof one block, project from the recess of that block into the recess ofan adjoining block and engage the back wall of the recess of theadjoining block, so that one anchoring clip For the purposes of thisinvention either type of anchoring effectively holds two adjoiningblocks in position.

clip is effective, for each type will serve to secure a wearresistantblock to a supporting base and prevent movement of the block on thebase.

The anchoring clip may be positioned against the rear wall of the recessat the time of installation of the block 1 on a base or it may be bondedto the rear wall of'the.

recess prior to installation. Generally it is preferred to bond the clipto the rear wall of the recess prior to instal-. lation, for thisfacilitates handling, insures that proper anchoring clips are used ininstallation, and facilitates installation, of the block. It has beenfound that clips may be firmly secured to the rear wall of the recess bymeans of a suitable adhesive, such as an epoxy resin.

The use of such a resin gives a good bond between the anchoring clip andthe block and holds up well even as the block is welded into place.

In order to understand more clearly the nature of accompanying drawingsshowing specific embodiments of abrasion-resistant blocks made inaccordance with the present invention, and in which:

FIGURE 1 is an exploded perspective view of one form of a wear-resistantblock made in accordance with this invention showing the block and theanchoring clip,

before the clip has been inserted into the recess of the block;

FIGURE 2 is a cross-sectional view of a block similar to that shown inFIGURE 1 and showing the clip inserted in the recess of the block andjoined to a supporting base;

FIGURE 3 is a cross-sectional view of the end of a.

block showing a modification of the rear wall of the recess;

FIGURE 4 is a cross-sectional view of .the end portion of a block madein accordance with this invention showing vanother modification of theanchoring clipandthe rear wall of the recess;

, FIGURES 5 and 5a are cross-sectional views of the end portion ofblocks showing another modification of the anchoring clip and the backwall of the recess;

FIGURE 6 is a perspective view of another form of a wear-resistant blockmade in accordance with this invention;

FIGURE 7 is a cross-sectional view of abutting blocks similar to thatshown in FIGURE 6;

FIGURE 8 is a perspective view of a plurality of wear-resistant blockssecured to a base forming an abrasion-resistant lining on the base.

Referring now more particularly to FIGURE 1, numeral 10 generallydesignates a fused cast refractory block suitable for use as awear-resistant element such as for achute lining. The block has top andbottom surfaces and substantially parallel side edge faces 11 andsubstantially parallel end edge faces 12. The side and end edge facesmay be either straight or beveled and for the purpose of illustrationonly end edge faces 12 are shown as being beveled in the same direction,While side edge faces 11 are straight. An anchoring clip receivingrecess -13 is formed at the base of one beveled end edge face of theblock and extends into the block. The recess has side walls and a rearwall 14, the Walls terminating below the top surface of the block. Therear wall 14 of the recess slopes into the block away from the edge face12. An anchoring clip 15 may be inserted into the recess 13 andpositioned against the rear wall 14 so that when the anchoring clip isjoined to a supporting base the clip will hold the block securely inposition, restraining it from upward movement.

FIGURE 2 shows more clearly the manner in which the anchoring clip holdsthe block in position on a base. This figure shows a block similar tothat shown in FIG- URE 1, the block having substantially parallel edgefaces 22 and 22 beveled in the same direction and a recess 23 formed atthe base of one beveled edge face. The rear wall 24 of the recess slopesinto the block away from the edge face 22 and the anchoring clip 25 ispositioned against the sloping recess wall. When the anchoring clip iswelded, as at 26 to a supporting base 27 the anchoring clip restrainsthe block from movement on the base and holds the block securely inposition. When a series of such blocks are secured in abutting relationon a base, the blocks are restrained from movement in any direction.

FIGURE 3 illustrates a modification of the wearresistant block shown inFIGURES 1 and 2. In this figure a block 30, having edge faces 32 beveledin the same direction, is provided with a recess 33 formed at the baseof one beveled edge face, the recess extending into the block. In thisillustration .the rear wall 34 of the recessed portion of the edge facehas a curved profile. The anchoring clip 35 conforms substantially inprofile to the profile of the rear wall 34 and engages a portion of thecurved rear wall. The anchoring clip is bonded to the rear wall by meansof an epoxy resin 38 to hold the clip in position. Upon welding, as at36, the clip 35 to a supporting base 37, the block is restrained frornupward movement on the base.

In the modification shown in FIGURE 4 the block 40 has straight edgefaces 42 and a recess 43 formed at the base of the edge face, the recessterminating below the top surface of the block. In this illustration therear wall 44 of the recess has a step or irregular profile and theanchoring clip 45 conforms substantially in profile to the profile ofthe rear wall. The anchoring clip engages a portion of the rear wall sothat when the clip is welded to a base the block is held securely inposition on the base.

FIGURE 5 shows a modification of the block in which the rear wall 54 ofthe recess 53 has a step profile and the anchoring clip 55 conformssubstantially in profile to the profile of the rear wall. The clip isbonded to the rear wall by means of an epoxy resin 58 and the anchoringclip engages a portion of the rear wall. FIG- URE 5a is a variation ofthe block shown in FIGURE 5 in which the anchoring clip 55 engages theentire rear wall 54' of the recess 53 which is formed at the base ofbeveled edge face 52.

FIGURE 6 illustrates another modification of an abrasion resistant blockmade in accordance with this invention. In this modification the block60 is cast with substantially parallel straight side edge faces 61 andsubstantially parallel straight end edge faces 62. Anchoring clipreceiving recesses 63 and 63' are formed at the bases of adjacent edgefaces 61 and 62, the rear walls of the recesses having :an irregular orstep profile, as shown at 74 and 74' in FIGURE 7. An anchoring clip therear recessed wall 64 is inserted partially within each recess andengages a portion of the rear wall thereof. A portion of the anchoringclip projects from the recess of one block and the projecting portion ofthe anchoring clip extends into the corresponding recess of an adjoiningblock to engage a portion of the rear wall of the recess of theadjoining block. In this manner a single anchoring clip 65 effectivelysecures two abutting blocks in position on a base.

The manner in which a single anchoring clip secures two abutting blocksin position is more clearly illus- 'trated in FIGURE 7. In this figureabutting blocks and 70', similar to block 60 in FIGURE 6, are held inposition on a base 77 by means of an anchoring clip welded at 76 to thebase. The anchoring clip engages a portion of the rear walls 74 and 74'of the recesses formed at the base of abutting edge faces 72 and 72 ofblocks 70 and 70 so that when the clip is welded to a base, movement ofthe blocks is prevented.

'FIGURE 8 illustrates the manner in which fused cast refractory blocksare assembled on a base, such as a chute, to form a wear-resistantlining on the chute. In this illustration a series of blocks 80, 80' and80", similar to that shown in FIGURE 1, are secured on a base 87. Theblocks 80 and 80' have substantially parallel straight side edge faces'82 and substantially parallel end edge faces 81, the end ed-ge facesbeing beveled in the same direction. An anchoring clip receiving recess84 is formed at the base of a beveled end edge face of each block, theback wall of the recess sloping into the block in the same manner asshown in FIGURES 1 and 2. An anchoring clip 85 is positioned against thesloping rear wall of each recess and the clip is welded at 86 to thebase 87. In order to form a continuous lining on the base, block 80" isfirst placed on the base and the anchoring clip welded to the base. Intheern-bodiment illustrated, block 80" has straight side edge faces, onestraight end edge face 88 and one beveled end edge face. Since thisblock is the first block in the course it is necessary to secure bothends of the block to the base. Therefore, end edge face 88 is providedwith an anchoring clip receiving recess (not shown) and secured to thebase by means of an anchoring clip (also not shown) inserted in therecess and welded to the base. The beveled end edge face is alsoprovided with a recess (shown in dotted lines) and an anchoring clip isinserted in the recess and welded to the base. In this manner block 80"is held securely in position on the base. Block 80 is then positioned onthe base so that the beveled edge faces of blocks 80' and 80" arejuxtaposed with the beveled edge faces parallel. In this manner the topsurface of the end of block 80" which is secured to the base overlapsthe end of the abutting block 80 which has no recess thereby restrainingthis end from movement. The opposing parallel end edge face of block 80,having a recess (shown in dotted lines), is then secured to the base bymeans of an anchoring clip, engaging the rear wall of the recess, beingwelded to the base. Block 80 is then secured to the base in a similarmanner so that the beveled end edge face which has no recess abuts andoverlaps the juxtaposed end edge face of block 80', so that the end ofblock 80' effectively holds the end of block 80 securely in position onthe base.

Example A fused cast refractory block, 12" x 6" x 2", composed ofcrystalline phases of zirconia and alumina in a glassy siliceous matrix,was made according to the disclosure of US. Patent No. 2,903,373. Themolten refractory composition was poured into a graphite mold havinggraphite inserts located at the base of one side of the mold. The blockthus formed consisted essentially of crystalline alumina and crystallinezirconia embedded and dispersed throughout a siliceous glassy matrix.The block was left in the mold for heat treatment and was carefullycooled by methods well known in the art. After the block had cooled, themold and insert were stripped from the block so that when the insert wasremoved a recess was formed at the base of an edge face of the block. Ametal anchoring clip, conforming in profile to the profile of the rearwall of the recess, was inserted in the recess and bonded to a portionof the rear wall by means of an epoxy resin. A series of such blocks wasthen fastened in abutting relation by welding the metal clips on a metalchute, thereby forming a wear-resistant lining on the chute.

It will be understood that the refractory mix described in the exampleWas given merely for the purpose of describing a suitable mix and thisinvention is not intended to be limited to fused cast refractory blocksmade from this specific composition. Rather, any fused cast refractoryhaving abrasion-resistant properties may be used in forming the blocks.

The size of the fused cast blocks will of course vary depending on theintended use of the blocks. Similarly, the size of the anchoring cliprecess is not a critical feature of this invention other than to providesufficient surface to enable the anchoring clip to hold the blocksecurely in position.

While the specification has primarily been concerned with the use of thefused cast refractory blocks as chute lining elements, the invention isnot intended to be limited to such a use alone. Rather, the blocks madein accordance with this invention are suitable for any use in whichresistance to Wear is a principal requirement, such as, for example,crusher housings, feeder tables, downcomers on blast furnaces and thelike.

While the invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodification, and this application is intended to cover any variations,uses or adaptations of the invention. It will therefore be recognizedthat the invention is not to be construed as limited to the preciseembodiments shown and described but is to be interpreted as broadly aspermitted by the appended claims.

We claim:

1. An abrasion-resistant article which comprises a fused cast refractoryblock having top and bottom surfaces, side edge faces and end edgefaces, said side edge faces being parallel and in spaced relation andsaid end edge rfaces being parallel and in spaced relation, one set ofsaid edge faces being beveled and having, at the base of that edge facewhich the top of said block overhangs, a recess, said recess extendinginto said block, having side walls, a top wall, and a rear wall, and ametal anchoring clip adhesively bonded solely to said rear wall of saidrecess,

8 saidclip being free of contact with the top wall of said recess.

2. An abrasion-resistant article as defined in claim 1 in which saidanchoring clip is wholly within said recess and has a portion flush withthe bottom surface of said block.

3. In a furnace chute having a metal base, the combination with saidbase of an abrasion-resistant lining comprising a series of fused castrefractory blocks, each of said blocks having top and bottom surfaces,side edge faces and end edge faces, said side edge faces being paralleland in spaced relation and said end edge faces 'being parallel and inspaced relation, one set of said edge faces being beveled and having, atthe base of that edge face which the top of said block overhangs, arecess, said recess extending into said block, having side walls,a topwall, and a rear wall, said blocks being held in place on said base by aplurality of metal anchoring clips a-t-. tached to said base, each ofsaid clips being wholly within a said recess of one of said blocks andbeing bonded to said block solely by adhesive attachment to said rearwall of said recess.

References Cited by the Examiner UNITED STATES PATENTS 283,012 8/1883Morton et a'l. 52-509 1,615,750 1/ 1927 Fulcher 106-55 2,056,732 10/1936 Melqler 52-249 2,216,784 10/ 1940 Payne 2-9-25 6 2,251,910 8/ 1941Beecher 52487 2,262,973 11/ 1941 Sonnenschein 52--509 2,3555 5 11/ 1943Willson 52-7 47 2,433,-17 5 12/ 1947 Urmetz 52-509 X 2,460,052 1/ 1949Werner 52-509 X 2,903,373 9/ 1959 S'andmeyer a- 106-57 3,178,492 4/1965Ross w 52-513 X FOREIGN PATENTS 576,628 5/ 1959 Canada.

OTHER REFERENCES The Iron Age, TS 200.18, 10-61, page 15.

Cor hardt AB-R, publication by Corhardt Refractories Co. Inc., 940Commonwealth Building, Louisville, Ky. Copyright November 25, 1961, 8pages.

RICHARD W. COOKE, JR., Primary Examiner.

FRANK L. ABBOTT, Examiner.

A. C. PERI-1AM, Assistant Examiner.

1. AN ABRASION-RESISTANT ARTICLE WHICH COMPRISES A FUSED CAST REFRACTORYBLOCK HAVING TOP AND BOTTOM SURFACES, SIDE EDGE FACES AND END EDGEFACES, SAID SIDE EDGE FACES BEING PARALLEL AND IN SPACED RELATION ANDSAID END EDGE FACES BEING PARALLEL AND IN SPACED RELATION, ONE SET OFSAID EDGE FACES BEING BEVELED AND HAVING, AT THE BASE OF THAT EDGE FACEWHICH THE TOP OF SAID BLOCK OVERHANGS, A RECESS, SAID RECESS EXTENDINGINTO SAID BLOCK, HAVING SIDE WALLS, A TOP WALL, AND A REAR WALL, AND AMETAL ANCHORING CLIP ADHESIVELY BONDED SOLELY TO SAID REAR WALL OF SAIDRECESS, SAID CLIP BEING FREE OF CONTACT WITH THE TOP WALL OF SAIDRECESS.